Gain Values
Regardless of your gyro type, you must set an appropriate gain value. The gain value
tells the gyro how much it needs to amplify the compensation commands. Too low of
a gain value will let the tail drift easily, and too high of a gain valve will make the
gyro overcompensate which results in a tail that “wags.” A good starting point is
50%, then adjust it as necessary after your test flights.
Any change that effects the speed or efficiency of the main or tail rotors can result in
a need to change the gain value. Some of the factors include:
●
Changes to your throttle or pitch curves
●
Changing the length or type of main or tail rotor blades
●
Forward flight, backward flight, or flight in a steady breeze (increases
efficiency because it brings lessturbulent air to the rotors.)
●
Pinion gear, main gear and motor
●
Tail drive gears / pulleys
Compensation Mixers, and Channels 7 / 8
Your remote control helicopter's setup is now complete. This section covers optional use of the two
available compensation mixers. A CMix will mix one channel with another, allowing you to link them.
Some of the reasons for the using the CMix include:
Reduce CCPM Interactions
CCPM interactions occur when an unintended swash plate movement results from a control
input. For example, when applying a full collectivepitch command, your swash plate may also
tilt forward slightly which would add an unintended forward cyclic effect. This is the result of
imperfect linkage geometry, and the fact that no two servos are completely alike.
You can mix Pitch to Aileron and/or Pitch to Elevator to counteract this effect.
Help Maintain a Constant HeadSpeed Without Using a Governor
Any cyclic control input will place a higher load to your main rotor. This increased load will
reduce the head speed, and in more demanding maneuvers this change can be significant. By
mixing Aileron to Throttle and Elevator to Throttle, you can help compensate the increased load.
This should only be done after properly adjusting your throttle and pitch curves to achieve a
nearly constant head speed throughout your pitch range.
The RaptorTechnique* website has a great tutorial on how to set this up:
http://www.raptortechnique.com/throttlemix.htm
Link a Channel to Your 7
th
or 8
th
Channel.
This just links one channel to another. You choose a upper and lower percentage, and that will
effect how much the two channels correlate. This will give you indirect proportional control over
your 7
th
and 8
th
channels if so desired.
*RaptorTechnique.com is not affiliated with Airtronics or Global Hobby Distributors.
